On Mon, 2012-09-10 at 11:13 +0200, Christian K?nig wrote: > Only increase the higher 32bits if we really detect a wrap around. > > Fixes: > https://bugs.freedesktop.org/show_bug.cgi?id=54129 > https://bugs.freedesktop.org/show_bug.cgi?id=54662 > > Possible fixes: > https://bugzilla.redhat.com/show_bug.cgi?id=846505 > https://bugzilla.redhat.com/show_bug.cgi?id=845639 > > Signed-off-by: Christian K?nig <deathsimple at vodafone.de> > Cc: stable at vger.kernel.org > --- > drivers/gpu/drm/radeon/radeon_fence.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/radeon/radeon_fence.c > b/drivers/gpu/drm/radeon/radeon_fence.c > index 7b737b9..4781e13 100644 > --- a/drivers/gpu/drm/radeon/radeon_fence.c > +++ b/drivers/gpu/drm/radeon/radeon_fence.c > @@ -160,7 +160,7 @@ void radeon_fence_process(struct radeon_device *rdev, int > ring) > do { > seq = radeon_fence_read(rdev, ring); > seq |= last_seq & 0xffffffff00000000LL; > - if (seq < last_seq) { > + if (seq < (last_seq - 0x80000000LL)) { > seq += 0x100000000LL; > }
Can you provide a bit more explanation for this change? In particular, how could the code previously detect a wraparound when there was none, and why is this the proper fix? -- Earthling Michel D?nzer | http://www.amd.com Libre software enthusiast | Debian, X and DRI developer
